Enhanced Plasmonic Photocatalysis through Synergistic Plasmonic-Photonic Hybridization

Plasmonic nanoparticles (NPs) hold tremendous promise for catalyzing light-driven chemical reactions. The conventionally assumed detrimental absorption loss from plasmon damping can now be harvested to drive chemical transformations of the NP adsorbent, through the excitation and transfer of energetic "hot"charge carriers. The rate and selectivity of plasmonic photocatalysis are dependent on the interaction between light and NPs. By engineering the strength and wavelength of the light harvesting of a NP, it is possible to achieve more efficient and selective photocatalysts. We report a plasmonic-photonic resonance hybridization strategy to substantially enhance hot electron generation at tunable, narrow-band wavelengths. By coupling the plasmon resonance of silver NPs to the guided mode resonance in a dielectric photonic crystal slab, the hot-electron-driven reduction conversion is greatly accelerated at a low illumination intensity. Broadly compatible with NPs with manifold materials and shapes that are optimized for the targeted chemistry, the generic hybrid enhancement mechanism sheds light on rational design of high-performance plasmonic photocatalysts.